This research is designed to provide a thorough and systematic analysis of the behavioral effects of alcohol and of factors that determine those effects. Specific experiments, using primarily the schedule-controlled responding of squirrel monkeys, will focus initially on documenting the various behavioral effects of alcohol under a wide variety of environmental conditions. These studies will include a comparison of the effects of alcohol on behaviors maintained or controlled by radically different consequent events (e.g., appetitive versus noxious stimuli), as well as studies that investigate the effects of alcohol on behaviors that are differently controlled by similar events. This will permit a relatively complete account of the manner in which alcohol's behavioral effects depend on the precise environmental circumstances that exist when the drug is given. Throughout this initial phase, the effects of alcohol will be compared with other drugs that are also either socially abused or are clinically prescribed. The results of experiments in the initial phases of this research program will then allow an analysis of the combined effects of alcohol and other drugs on behavior. The study of alcohol-drug interactions will proceed concurrently with investigation of the effects on behavior of chronic alcohol administration. An objective of particular interest in these experiments consists of documenting the development of behavioral tolerance to alcohol, the conditions under which tolerance occurs, and whether the chronic administration of alcohol modifies the manner in which alcohol interacts with other drugs. These studies will provide useful information to both behavioral and pharmacological analyses of the multiple determinants of the actions of alcohol.